14807-05-7

Basic information

• Product Name: Rhamnulose
• Synonyms: 6-Deoxy-L-sorbose;L-Rhamnulose;Rhamnulose;6-Deoxy-L-arabino-2-hexulose
• CAS NO: 14807-05-7
• Molecular Formula: C₆H₁₂O₅
• Molecular Weight: 164.15648
• Mol File: 14807-05-7.mol

Chemical Properties

• Boiling Point: 323.9°Cat760mmHg
• Flash Point: 149.7°C
• Appearance: /
• Density: 1.556g/cm³
• BRN: 1723712
• CAS DataBase Reference: Rhamnulose(CAS DataBase Reference)
• NIST Chemistry Reference: Rhamnulose(14807-05-7)
• EPA Substance Registry System: Rhamnulose(14807-05-7)

Safety Data

• WGK Germany: 3
• Hazardous Substances Data: 14807-05-7(Hazardous Substances Data)

Upstream product

• 110-86-1 pyridine 
• 2438-80-4 L-Fucose 
• 92418-41-2 L-Fuculose-1-phosphate 
• 73804-38-3 1-deoxy-L-altritol 
• 38088-18-5 1-deoxy-L-psicose 
• 3615-41-6 L-Rhamnose 
• 96-26-4 dihydroxyacetone 
• 3913-64-2 2(S)-hydroxypropanal 
• 10030-85-0 L-rhamnose monohydrate 
• 3913-65-3 2-hydroxypropanal 
• 488-28-8 L-rhamnitol 
• 3616-21-5 6-deoxy-L-psicose 
• 73-34-7 L-rhamnose 
• 444-09-7 L-rhamnulose 1-phosphate 

Downstream Products

• 7658-10-8 6-Deoxy-L-talose 
• 72774-23-3 6-deoxy-L-fructose 2-nitrophenylhydrazone 
• 35867-45-9 6-deoxy-L-glucose 
• 128613-49-0 C₁₀H₁₃NO₃ 

Relevant articles and documents

Base catalysed isomerisation of aldoses of the arabino and lyxo series in the presence of aluminate

Base-catalysed isomerisation of aldoses of the arabino and lyxo series in aluminate solution has been investigated. L-Arabinose and D-galactose give L-erythro-2-pentulose (L-ribulose) and D-lyxo-2-hexulose (D-tagatose), respectively, in good yields, whereas lower reactivity is observed for 6-deoxy-D-galactose (D-fucose). From D-lyxose, D-mannose and 6-deoxy-L-mannose (L-rhamnose) are obtained mixtures of ketoses and C-2 epimeric aldoses. Small amounts of the 3-epimers of the ketoses were also formed. 6-Deoxy-L-arabino-2-hexulose (6-deoxy-L-fructose) and 6-deoxy-L-glucose (L-quinovose) were formed in low yields from 6-deoxy-L-mannose and isolated as their O-isopropylidene derivatives. Explanations of the differences in reactivity and course of the reaction have been suggested on the basis of steric effects.

Structure-based studies on the metal binding of two-metal-dependent sugar isomerases

Two-metal-dependent sugar isomerases are important in the synthesis of rare sugars. Many of their properties, specifically their metal dependency, have not been sufficiently explored. Here we used X-ray crystallography, site-directed mutagenesis, isothermal titration calorimetry and electron paramagnetic resonance spectroscopy to investigate the molecular determinants of the metal-binding affinity of l-rhamnose isomerase, a two-Mn2+-dependent isomerase from Bacillus halodurans (BHRI). The crystal structure of BHRI confirmed the presence of two metal ion-binding sites: a structural metal ion-binding site for substrate binding, and a catalytic metal ion-binding site that catalyzes a hydride shift. One conserved amino acid, W38, in wild-type BHRI was identified as a critical residue for structural Mn2+ binding and thus the catalytic efficiency of BHRI. This function of W38 was explored by replacing it with other amino acids. Substitution by Phe, His, Lys, Ile or Ala caused complete loss of catalytic activity. The role of W38 was further examined by analyzing the crystal structure of wild-type BHRI and two inactive mutants of BHRI (W38F and W38A) in complex with Mn2+. A structural comparison of the mutants and the wild-type revealed differences in their coordination of Mn2+, including changes in metal-ligand bond length and affinity for Mn2+. The role of W38 was further confirmed in another two-metal-dependent enzyme: xylose isomerase from Bacillus licheniformis. These data suggest that W38 stabilizes protein-metal complexes and in turn assists ligand binding during catalysis in two-metal-dependent isomerases.

Production of l-rhamnulose, a rare sugar, from l-rhamnose using commercial immobilized glucose isomerase

A commercial immobilized d-glucose isomerase from Streptomyces murines (Sweetzyme) was used to produce l-rhamnulose from l-rhamnose in a packed-bed reactor. The optimal conditions for l-rhamnulose production from l-rhamnose were determined as pH 8.0, 60 °C, 300 g?L?1 l-rhamnose as a substrate, and 0.6 h?1 dilution rate. The half-life of the immobilized enzyme at 60 °C was 809 h. Under the optimal conditions, the immobilized enzyme produced an average of 135 g?L?1 l-rhamnulose from 300 g?L?1 l-rhamnose after 16 days at pH 8.0, 60 °C, and 0.6 h?1 dilution rate, with a productivity of 81 g/L/h and a conversion yield of 45% in a packed-bed reactor.

Enzymatic production of three 6-deoxy-aldohexoses from L-rhamnose

6-Deoxy-L-glucose, 6-deoxy-L-altrose, and 6-deoxy-L-allose were produced from L-rhamnose with an immobilized enzyme that was partially purified (IE) and an immobilized Escherichia coli recombinant treated with toluene (TT). 6-Deoxy-L-psicose was produced from L-rhamnose by a combination of L-rhamnose isomerase (TT-PsLRhI) and D-tagatose 3-epimerase (TT-PcDTE). The purified 6-deoxy-Lpsicose was isomerized to 6-deoxy-L-altrose and 6-deoxy-L-allose with L-arabinose isomerase (TT-EaLAI) and L-ribose isomerase (TT-AcLRI), respectively, and then was epimerized to L-rhamnulose with immobilized D-tagatose 3-epimerase (IE-PcDTE). Following purification, L-rhamnulose was converted to 6-deoxy-L-glucose with D-arabinose isomerase (TT-BpDAI). The equilibrium ratios of 6-deoxy-L-psicose:6-deoxy-L-altrose, 6-deoxy-L-psicose:6-deoxy-L-allose, and L-rhamnulose:6-deoxy-L-glucose were 60:40, 40:60, and 27:73, respectively. The production yields of 6-deoxy-L-glucose, 6-deoxy-L-altrose, and 6-deoxy-L-allose from L-rhamnose were 5.4, 14.6, and 25.1%, respectively. These results indicate that the aldose isomerases used in this study acted on 6-deoxy aldohexoses.

Bioproduction of a novel sugar 1-deoxy-l-fructose by Enterobacter aerogenes IK7; isomerization of a 6-deoxyhexose to a 1-deoxyhexose

1-Deoxy-l-fructose, a very rare monosaccharide, was produced by hydrogenation of 6-deoxy-l-mannose (l-rhamnose)-the only cheaply available deoxy sugar-to 1-deoxy-l-mannitol (l-rhamnitol) followed by oxidation with Enterobacter aerogenes IK7. The entire procedure was conducted in water and shows the power of green environmentally friendly chemistry combined with biotechnology in the preparation of new monosaccharides with potential for novel bioactive properties or alternative foodstuffs; the reactions here are reported on a multigram scale but would be reproducible on a very large scale.

Characterization of a novel D-arabinose isomerase from Thermanaeromonas toyohensis and its application for the production of D-ribulose and L-fuculose

D-Ribulose and L-fuculose are potentially valuable rare sugars useful for anticancer and antiviral drugs in the agriculture and medicine industries. These rare sugars are usually produced by chemical methods, which are generally expensive, complicated and do not meet the increasing demands. Furthermore, the isomerization of D-arabinose and L-fucose byDD-arabinose and L-fucose by D-arabinose isomerase from bacterial sources for the production of D-ribulose and L-fuculose have not yet become industrial due to the shortage of biocatalysts, resulting in poor yield and high cost of production. In this study, a thermostable D-ribulose- and L-fuculose producing D-arabinose isomerase from the bacterium Thermanaeromonas toyohensis was characterized. The recombinant D-arabinose isomerase from T. toyohensis (Thto-DaIase) was purified with a single band at 66 kDa using His-trap affinity chromatography. The native enzyme existed as a homotetramer with a molecular weight of 310 kDa, and the specific activities for both D-arabinose and L-fucose were observed to be 98.08 and 85.52 U mg?1, respectively. The thermostable recombinant Thto-DaIase was activated when 1 mM Mn2+ was added to the reactions at an optimum pH of 9.0 at 75 °C and showed approximately 50% activity for both D-arabinose and L-fucose at 75 °C after 10 h. The Michaelis-Menten constant (Km), the turnover number (kcat) and catalytic efficiency (kcat/Km) for D-arabinose/L-fucose were 111/81.24 mM, 18,466/10,688 min?1, and 166/132 mM?1 min?1, respectively. When the reaction reached to equilibrium, the conversion rates of D-ribulose from D-arabinose and L-fuculose from L-fucose were almost 27% (21 g L?1) and 24.88% (19.92 g L?1) from 80 g L?1 of D-arabinose and L-fucose, respectively.

Efficient enzymatic synthesis of l-rhamnulose and l-fuculose

l-Rhamnulose (6-deoxy-l-arabino-2-hexulose) and l-fuculose (6-deoxy-l-lyxo-2-hexulose) were prepared from l-rhamnose and l-fucose by a two-step strategy. In the first reaction step, isomerization of l-rhamnose to l-rhamnulose, or l-fucose to l-fuculose was combined with a targeted phosphorylation reaction catalyzed by l-rhamnulose kinase (RhaB). The by-products (ATP and ADP) were selectively removed by silver nitrate precipitation method. In the second step, the phosphate group was hydrolyzed to produce l-rhamnulose or l-fuculose with purity exceeding 99% in more than 80% yield (gram scale).

6-Deoxyhexoses from l-Rhamnose in the Search for Inducers of the Rhamnose Operon: Synergy of Chemistry and Biotechnology

In the search for alternative non-metabolizable inducers in the l-rhamnose promoter system, the synthesis of fifteen 6-deoxyhexoses from l-rhamnose demonstrates the value of synergy between biotechnology and chemistry. The readily available 2,3-acetonide of rhamnonolactone allows inversion of configuration at C4 and/or C5 of rhamnose to give 6-deoxy-d-allose, 6-deoxy-d-gulose and 6-deoxy-l-talose. Highly crystalline 3,5-benzylidene rhamnonolactone gives easy access to l-quinovose (6-deoxy-l-glucose), l-olivose and rhamnose analogue with C2 azido, amino and acetamido substituents. Electrophilic fluorination of rhamnal gives a mixture of 2-deoxy-2-fluoro-l-rhamnose and 2-deoxy-2-fluoro-l-quinovose. Biotechnology provides access to 6-deoxy-l-altrose and 1-deoxy-l-fructose.

Molecular characterization of a thermostable l-fucose isomerase from Dictyoglomus turgidum that isomerizes l-fucose and d-arabinose

A recombinant thermostable l-fucose isomerase from Dictyoglomus turgidum was purified with a specific activity of 93 U/mg by heat treatment and His-trap affinity chromatography. The native enzyme existed as a 410 kDa hexamer. The maximum activity for l-fucose isomerization was observed at pH 7.0 and 80 °C with a half-life of 5 h in the presence of 1 mM Mn2+ that was present one molecular per monomer. The isomerization activity of the enzyme with aldose substrates was highest for l-fucose (with a kcat of 15,500 min-1 and a Km of 72 mM), followed by d-arabinose, d-altrose, and l-galactose. The 15 putative active-site residues within 5 A of the substrate l-fucose in the homology model were individually replaced with other amino acids. The analysis of metal-binding capacities of these alanine-substituted variants revealed that Glu349, Asp373, and His539 were metal-binding residues, and His539 was the most influential residue for metal binding. The activities of all variants at 349 and 373 positions except for a dramatically decreased kcat of D373A were completely abolished, suggesting that Glu349 and Asp373 were catalytic residues. Alanine substitutions at Val131, Met197, Ile199, Gln314, Ser405, Tyr451, and Asn538 resulted in substantial increases in Km, suggesting that these amino acids are substrate-binding residues. Alanine substitutions at Arg30, Trp102, Asn404, Phe452, and Trp510 resulted in decreases in kcat, but had little effect on Km.

Redesign of the phosphate binding site of L -rhamnulose- 1-phosphate aldolase towards a dihydroxyacetone dependent aldolase

The aldol addition of unphosphorylated dihydroxyacetone (DHA) to aldehydes catalyzed by L-rhamnulose-1-phosphate aldolase (RhuA), a dihydroxyacetone phosphate-dependent aldolase, is reported. Moreover, a single point mutation in the phosphate binding site